Many devices include connectors for receiving a wired connection to another device. Various types of connectors can be found in the marketplace that can be configured for a particular combination of characteristics. In one instance, a design consideration for a particular connector includes circuitry to enhance the operation of the circuit with which the connector will be used. In another instance, design considerations for such connectors can include the cost, the desired reliability, the sensitivity of the connector to the environment, the ease with which the connection may be made, the expected number of cycles (connecting and disconnecting), the number of contacts required, and other considerations.
It may sometimes be important to know when a connection between two devices has been established. Some conventional connectors detect such electrical connections using a mechanical means. For example, a spring can be located at a port or other receiving interface, such that the spring is compressed when a connector is physically connected to the port.
In devices where size is an important design parameter, such as in a hearing aid, a spring-type of detector may consume too much space to be usable. Moreover, the spring may require an insertion (connection) force sufficient to compress the spring to establish the connection that may be impractical for soft tissues such as the tissues of the ear. Further, the spring represents a mechanical feature that may be prone to failure.
In some instances, circuitry can be used to detect a physical connection, such as a powered device detection circuit in a Power over Ethernet environment. However, such detection circuitry consumes power in the detection process, which power consumption is undesirable in small, portable, battery-powered devices, such as hearing aids.
In the following description, the use of the same reference numerals in different drawings indicates similar or identical items.